Apparatus for forming mineral fibers



June 6, 1967 R. M. DOWNEY 3,323,887

APPARATUS FOR FORMING MINERAL FIBERS Filed Nov. 7, 1962 3 Sheets-Sheet 1 5 Z0 y y /e O I O o, I v 0 22 49 O I o INVENTOR. fic'fiard/iflfl MfiWM Mme/ways- June 6, 1967 R. M. DOWNEY 3,323,837

' APPARATUS FOR FORMING MINERAL FIBERS Filed Nov. 7, 1962 3 Sheets-Sheet :3 H I H l i I I/ INVENTOR i/fiaM/V. flan/223g,

R. M. DOWNEY June 6, 1967 APPARATUS FOR FORMING MINERAL FIBERS 5 Sheets-Sheet 35 Filed Nov. '7, 1962 m E m V INVENTOR flay/8rd fiawne? BY United States Patent ()fifice 3,323,387 Patented June 6, 1967 3,323,887 APPARATUS FOR FORMING MINERAL FIBERS Richard M. Downey, Rte. 1, Roann, Ind. 46974 Filed Nov. 7, 1962, Ser. No. 235,978 11 Claims. (CI. 65-14) The present invention relates to an improved apparatus and method for forming mineral fibers and the like from suitable inorganic materials such as slag, scoria and glass.

The conversion of such inorganic materials into filaments or fibers, forming such products as mineral or glass wool, has been accomplished in the past by means of apparatuses and methods which employed gaseous blasts and mechanical devices either alone or in combination with each other. Gaseous blasts, usually in the form of steam, have been used by directing the same against a gravitating stream of molten slag or similar material for the purpose of dispersing the stream into a multiplicity of droplets and streamlets and propelling them with sufficient force and velocity to cause a portion thereof to become elongated and solidified into more or less fine fibers. The disadvantages of using such a gaseous blast alone are now well known. Mechanical devices in the form of centrifuging distributors have been used to divide and subdivide a gravitating slag stream into smaller streams which are propelled outwardly with enough force such that they eventually attenuate and solidify into a fibrous product. Then, apparatuses and methods employing both centrifugal distributors as well as gaseous blasts have been used' such that a gravitating stream of molten slag is centrifuged outwardly by the distributor into the path of a gaseous blast which acts directly onto a centrifuged material for converting the same into filamentous or fiberous form. The present invention is primarily concerned with the provision of improvements in these latter mentioned apparatuses and methods.

More specifically, in the use of an apparatus employing both a mechanical distributor and gaseous blast, a stream of molten thermal-plastic material is first applied to the distributor which generates centrifuging forces in excess of the cohesive forces of the materials surface tension. This results in the molten material being centrifuged from the distributor in the form of a multiplicity of minute, filamentary streams and masses, these then being subjected to the attenuating and solidifying action of a suitable gaseous blast.

If the discharge streams or masses are too fluid, no filaments will be formed therefrom, since surface tension causes them to contract into a spen'cal form. Also, if the attenuating action of the gaseous blast is not prolonged until solidification occurs, surface tension will again cause the still fluid filamentary streams to regress into the spherical form. Further, if the attenuating forces of the gaseous blast are not of suflicient velocity or are ineffectually applied, optimum attenuation of the fluid streams and masses may not be achieved.

The solidified spherical masses, termed shot, constitute a significant portion of the total fibrous product produced such that the elimination, reduction or separation thereof has long been a most important object of the fiber-forming arts.

Centrifugal separation, usually accomplished by directing an attenuating blast through a restricted aperture, has provided a means for separation of some of the larger globules; however, this approach has proven to be of little value with respect to the separation of globules from attached fibers or those produced by insuificient attenuating action inasmuch as both are conveyed directly in the attenuating blast.

An evaluation of these prior arts, commercially acceptable apparatuses and processes indicates that they are capable of producing no greater than approximately thirty-five percent (35%) of true fibers from a given amount of molten thermal-plastic material. It is with respect to improving efficiency and increasing fiber yield to which this present invention is primarily directed. Actual working models of this invention result in fiber production of at least 50%, which represents an increased efficiency of approximately 43%.

It is, therefore, an object of this invention to provide an improved apparatus and method for converting molten thermal-plastic material into fibrous form.

It is another object of this invention to provide an apparatus for converting molten material into fibrous form through the use of a centrifugal distributor and attenuating means whereby the attenuation of filamentous streams of material centrifuged from the distributor may be of a continued and prolonged nature thereby increasing the percentage of fiber to shot in the total products as compared to that achieved by means of prior apparatuses.

'It is still another object of this invention to provide an apparatus for fabricating mineral fibers which is more efficient and economical in the operation thereof, and affords a greater latitude in design in the accomplishment of these advantages.

Other objects will become apparent as the description proceeds.

Broadly, an apparatus of this invention includes a centrifuging distributor having an upwardly exposed, materialreceiving surface, means for rotating this distributor about a substantially vertical axis, delivery means for directing a gravitating stream of molten material onto said material-receiving surface and means for directing a gaseous blast inclined upwardly and forwardly at a relatively small angle and in a given general direction against molten material centrifuged from said surface for attenuating and solidifying said centrifugal material into fibers.

More specifically, a typical apparatus of this invention comprises a cylindrical rotor having a vertically extending shaft and an upwardly exposed slag-receiving surface, said surface being spherically concave and having a periphery which defines and lies in a substantially horizontal plane. A supporting frame mounts the shaft and rotor for rotation about a vertical axis, the rotor being disposed on the upper end of the shaft. The shaft and rotor preferably are hollow coaxially to receive therein an upright tube having a discharge end located either in or adjacent to the rotor. The tube has a radial clearance with the hollow shaft, thereby providing a discharge duct having inner and outer walls defined by the pipe and shaft respectively. Water for cooling purposes may be circulated through the tube into the rotor and out of the discharge duct.

A housing having diametrically opposite spaced apart front and rear portions is mounted on the frame and constitutes a chamber which surrounds the rotor. The housing includes an upwardly disposed substantially fiat horizontal plate provided with a central opening through which said rotor face projects, the plane of .the rotor periphery lying above the upper surface of the plate in close proximity thereto. The plate is provided with a series of spaced apart jet passages therethrough which are arranged in a pattern surrounding .the rotor, and communicate with the chamber. This pattern is eccentric with respect .to the rotor, in one embodiment of this invention, and may be regarded as being composed of two sections. One arcuate section extends around the front portion of said housing for a length of approximately 315, and is substantially bisected by a. vertical plane which includes a diameter of said rotor surface. The passages of this one section are inclined in a given forward direction at an angle of about 35 to the horizontal, and are substantially parallel to the aforesaid vertical plane.

The second arcuate section of the aforementioned pattern is also substantially bisected by said vertical plane and has a length of approximately 45. The innermost passages of said second section adjacent the vertical plane incline upwardly and forwardly at an angle of approximately 35 with respect to the horizontal and diverge outwardly at an approximate angle of 30 with respect to said vertical plane. The remaining passages of this second section incline upwardly and forwardly at an angle of approximately 35 with the horizontal and decrease progressively in divergency outwardly from said inner passages until theybecome parallel to said vertical plane at .the end extremities of said one arcuate section. This second arcuate section thereby extends around the rearmost portion of the housing.

All of the aforementioned passages have axes respectively which when extended intersect the plane of the rotor periphery in a substantially circular pattern concentric with and spaced outwardly from the rotor periphery.

A slag trough is disposed above the rotor surface and delivers a gravitating stream of molten slag onto that portion of the surface which lies within the angle of divergency between the aforementioned inner passages. It is important that this trough be disposed above the path of the passage axes. Means are provided for filling the aforesaid chamber with steam under pressure which issues from said series of passages in the form of an enveloping inclined blast, and other means are provided for rotating the rotor. The mass of the steam and the rotational speed of the rotor are related such that molten slag is centrifuged from the rotor surface in filamentary streams which are intercepted by said blast. The rotational speed of the rotor is insufficient to centrifuge said filamen-tary streams through the encircling steam blast such that the latter can act on and attenuate .the streams into finished fibers. By reason of the inclination of the steam blast and the substantially horizontal discharge from the rotor, successive and prolonged action of the blast on the centrifuged material results: this provides an increase in the percentage of finished fiber and a corresponding reduction in shot.

The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side elevation, partially broken away and sectioned for clarity, of an embodiment of this invention;

FIG. 2 is a top plan view of the same apparatus with the slag trough being omitted;

FIG. 3 is a part sectional illustration of the horizontal rotor and surrounding chamber whereby an inclined blast of steam or the like may be directed past the rotor periphery;

'FIG. 4 is a side view, similar to FIG. 3, used in explaining some of the dimensional aspects of this invention;

FIG. 5 is a sectional view of the hollow rotor and shaft construction;

FIG. 6 is a graph used in explaining the operational features of this invention;

FIG. 7 is a top plan view in diagrammatic form of the rotor and jet pattern and is used in explaining the operation of this invention; and

FIG. 8 is another diagrammatic illustration in vertical elevation used in explaining the operation of this invention.

Referring to the drawings, and more particularly to FIGS. 1 through 5, the apparatus comprises a generally cylindrical rotor 10 having an upwardly exposed, spherically concave face or slag-receiving surface 12. As is more clearly shown in FIG. 5, the periphery of this face 12 lies substantially in a horizontal plane.

4 The rotor 10 is supported for rotation about its axis which is substantially vertical by means of a hollow shaft 14, the rotor 10 being mounted on and fixedly secured to the upper end of the shaft 14; A suitable supporting frame, generally indicated by .the reference numeral 16, mounts a bearing 18 in which the aforementioned shaft 14 is joumaled, rotation being provided by means of a suitable belt and pulley combination 20 operatively connected to an electric motor 22 also mounted on the frame 16. Operation of the motor 22 results in rotation of the shaft 14 as well as the rotor 10.

A tube 24 of smaller size than the bore 26 of the shaft 14 is coaxially inserted into the bore and positioned with its discharge end 28 adjacent the cavity 30 in the rotor. The lower end of the tube 24 is threadedly secured to a coupling 32 which in turn is suitably mounted in the bottom end of a water-collecting cup 34 suitably fastened to the frame 16. This cup 34 receives the lower end portion of the hollow shaft 14 and is provided with a drain 36. Water may be continuously circulated through the coupling 32, tube 24, and into the cavity 30 of the rotor from which it can return under pressure downwardly through the annular passage between the tube 24 and bore 26 into the cup 34 and out of the drain 36.

Adjustment of the quantity of the water so circulated is simply accomplised by means of a conventional valve connected in series with the fluid line leading to the coupling 32. Also, ready adjustment of the rotational speed of the rotor 10 may be accomplished through the use of a variable speed motor or by means of a variable speed pulley system of conventional construction.

Securely mounted on the upper portion of the frame 16 is a housing generally indicated by the numeral 38. While this housing 38 may take any of several different forms, in a working embodiment of this invention as shown in the drawings, it comprises two concentric, cylindrical sides 40 and 42 which are spaced apart as shown, and two flat and substantially horizontal upper and lower plates 44 and 46, respectively. These sides and plates are suitably secured together by welding or the like such that they provide a closed annular plenum chamber 48. Steam is admitted to the rearmost section of chamber 48 by means of a suitably inclined inlet 59, the angle of inclination being approximately 35 with the horizontal or alternatively approximately equal to the angle of inclination of passages 58. Also the inlet 50 is aligned and inclined axially with the rotor diameter indicated by the numeral 66.

A vertical baflle or partition 52 is fitted between the chamber sides 40, 42, 44 and 46 in the front portion of the chamber in alignment with the diametral line 66 of the rotor.

The lower plate 46 is provided with an opening 54 which receives the shaft 14 therethrough.

The rotor 10 is mounted inside of the wall 42 and projects through a clearance opening 56 in the upper plate 44 to a level slightly above the surface of the latter.

A series of jet passages 58 are drilled or formed through the upper plate 44 in communication with the chamber 48, these passages 58 being closely spaced in a pattern encircling the rotor 10 as shown more clearly in FIG. 2. More specifically,'the shape of this pattern'is'slightly elliptical or eccentric with respect to the rotor. The reason for using this particular pattern will be explained more fully hereinafter.

As shown more clearly in FIG. 3, these passages 58 are inclined upwardly at an acute angle. The eccentric pattern of the passages as shown in FIG. 2 may "be regarded as being divided into two arcs or arcuate sections, the larger one being indicated by the reference numeral 60 and the smaller one by the reference numeral 62. These two arcuate sections may be further identified as extending between the sides 64a and 64b of an angle having its apex at the geometric center of the rotor'lO, in one embodiment of this invention the arcuate extent of the secamass? tion 60 being 315 and the extent of the section 62 being 45. These two arcuate sections 60 and 62 are substantially bisected by a vertical plane 66 which includes a diameter of the rotor 10, this plane as it appears in FIG. 2 extending between the rear and front portions 68 and 70, respectively, of the housing 38 and rotor 10. For convenience in describing the invention, an arrow 72 constituting a rightward extension of the plane 66 indicates a forward direction.

It may now be stated that all of the passages 58 in the arcuate section 60 are substantially parallel to each other and to the vertical plane 66 and furthermore are inclined forwardly at an acute angle with the horizontal. The passages 58 which make up the arcuate section 62 are also inclined forwardly at substantially the same acute angle to the horizontal but in addition are also diverged away from the opposite respective sides of the vertical plane 66. For example, the passages 58a and 581; immediately adjacent to the opposite sides, respectively, of the vertical plane 66 diverge at angles of 30 away from the plane 66 along the respective lines 5912 and 59b. The remaining passages of this arcuate section outwardly from the inner passages 53a and 58b also diverge but decrease progressively in divergency until the terminal passages 61 and 63 of section 62 become parallel to plane 66.

Further locationing of the passages 58 is determined by projecting the axes thereof until they intersect the plane 74 of the rotor periphery in a circle which is substantially concentric with and spaced outwardly from the periphery. As shown in FIG. 4, the axis 76 of a rear passage and another axis 78 of a front passage intersect the plane of the rotor periphery at points approximately equidistant from the latter.

Steam under pressure introduced into the plenum chamber 48 will emerge through the pattern of jet passages 58 and thereby form an enveloping blast pattern 80 (FIG. 1) which inclines upwardly and forwardly at an approximate angle of 30 to 35. By reason of the divergencies of the passages making up the arcuate section 62, a well or opening in the enveloping jet blast 80 will be developed roughly along and between the lines 59a and 59b. The reason for providing this well will be explained more fully hereinafter.

Referring to FIG. 1, a slag trough 82 is mounted for longitudinal adjustment in the directions of the arrow 84 by means of a rack and pinion 86, and additionally is laterally adjustable by means of a pivot connection 88. Inclination of the trough 82 may be adjusted by means of a horizontal pivotal connection 90 which secures the trough assembly to suitable supporting structure (not shown). As suitable melting furnace 92 is situated with its discharge port immediately above the trough 82 such that a stream 4 of melt from the furnace 92 will be guided by the trough onto the upper face 12 of the rotor 10. The trough 82 which receives the stream 94 is so adjusted with respect to the rotor that the discharged stream 96 gravitates through the well 59a, 59b previously described and onto the rotor surface 12.

In operation, a stream of the fiber-forming thermalplastic material 94 is gravitationally directed onto the central portion of the upwardly exposed surface 12 of the rotor 10 and is centrifugally discharged from the latte-r in the form of minute, semi-plastic filaments and masses Which are forcibly projected into the encircling, angularly directed fluid blast 80. This fluid blast further attenuates and subsequently solidifies these filaments and masses into final fibrous form.

As shown more clearly in FIG. 1, the lower extremity of the melt stream 96 angles somewhat forwardly as it approaches the rotor surface such that it is necessary to adjust the trough 82 rearwardly to a point at which the stream 96 ultimately contacts the central portion of the rotor face 12. This stream deflection is caused by draft induced by the stream blast 84' this draft moving forwardly across the rear portion of the housing 38.

The force of centrifuging the molten material from the rotor 10 should be of suflicient magnitude to project the semiplastic filaments and masses properly into the encircling, angularly directed blast so as to permit optimum attenuation thereof. This condition is established by adjusting the speed of the rotor 10 slightly below that at which the projected filaments and masses penetrate through the blast 80. This adjustment is readily effected by visual observation of the fiber-forming process during variation of rotor speed. FIG. 6 is a graphical interpretation of the effect of centrifuging speed with respect to efficiency under specific operating conditions and illustrates the importance of maintaining an optimum centrifuging force. Inasmuch as the physical properties of the fiber-forming material may vary by reason of changes in chemical composition, temperature or volume, this ca pability of the apparatus to adjustment for optimum efficiency is significant and constitutes a particular advantage of the present invention over prior art arrangement which were less susceptible of such optimum adjustment.

The horizontal arrangement of the rotor face in combination with the angular inclination of the gaseous blast 80 directly contribute to improvements in efficiency, economy and quality of the final product. As explained earlier, it is important in connection with the formation of the finally solidified fibers to minimize as much as possible regression of filamentary streamlets into globules which solidify as sho By subjecting the centrifuged material to prolonged and successive forces of attenuatio-n, regression is inhibited thereby resulting in a greater fiber-to-shot yield. By directing the encircling .blast 80 at an acute angle to the plane of centrifuging, the blast pattern in cross-section becomes elliptical in shape. The minor axis of this elliptical shape diminishes proportionately as the size of the acute angle reduces such that the cross-section of the blast 80 in regions forwardly of the rotor become more and more concentrated or solid in form. This substantially sold cross-section of the blast results in an intensification and prolongation of the attenuating forces acting on the centrifuged material such that, as stated previously, a greater fiber yield is realized.

An understanding of the concentrated form of the blast 80 is made easier by comparing the configuration of this particular blast with the same blast if it were directed vertically at an angle of with the plane of the rotor face. This latter arrangement compares with the apparatus disclosed in my Patent No. 2,729,849 wherein the rotor face was positioned vertically and the steam projected horizontally in a sleeve-like blast surrounding the rotor. By reason of the perpendicular relationship between the steam blast and the rotor face, a reverse draft or curent of air, which may be characterized as a core, flowed through the steam sleeve. This resulted in the steam sleeve moving forwardly and a central core of air moving rearwardly or oppositely. Quite obviously, these counterforces reduced the velocity of the steam blast and the material carried therein, thereby weakening the attenuating effect of the steam blast. In other words, once the velocity of the steam blast outwardly from the rotor face drops below a certain critical value, it no longer can exert any attenuating force on fluid or semi-plastic filaments. It therefore becomes desirable to extend and prolong as much as possible the steam blast and the attenuating forces thereof, and way of accomplishing this is to minimize or eliminate the core of return draft.

By reason of the expansion properties of the steam as well as the angular inclination of the blast 80 as shown in FIG. 1, the blast 80 will be substantially filled, in crosssection, with steam, such that little or no return draft through the middle portion thereof can occur. Also, as stated previously, the acute angle of the blast 80 results in the cross-sectional shape of the blast being elliptical which, in turn, results in substantially, physically closing any core or opening which might tend to develop in the central portion of the blast.

NOW, if it is considered that the blast 80 is substantially solid in cross-section, it immediately will be understood that this entire cross-section is available for exerting the necessary attenuating forces on the filamentary particles being conveyed therein in contrast to a cored blast.

An additional significant feature residing in the use of the inclined blast 80 resides in the fact that the majority of the centrifugally discharged filaments and masses are subjected to multiple attenuation forces in their somewhat semi-orbital passage in the blast. This may best be explained by reference to FIGS. 7 and 8 wherein the reference numeral 98 indicates a tangentially centrifuged semiplastic filament or mass. In following its tangential trajectory, the filament or mass eventually encounters, in succession, a series of jet streams 100 which intercept its tangential path. As the mass or filament encounters these streams 100, the latter each in succession intercept the filament and exert successive attenuating forces thereon. This is in distinct contrast with blasting the filament 98 with only a single steam jet whereby the filament is subjected only once to an attenuating force. Considering FIGS. 7 and 8 together, a tangentially discharged filament 102 projected in the direction indicated will encounter a series of jet streams and will be directed somewhat along a path as indicated by the heavier curved line in FIG. 8. The multitude of jet streams 104 in the vicinity of the origination of the stream 102 successively act on the filament to attenuate and elongate the same. While these illustrations in FIGS. 7 and 8 are diagrammatic only, they are useful in explaining the relationship of the component forces involved in the theory of this invention whereby greater production of fiber content in the total product is obtained.

Of significance is the fact that the rotor has its concave slag-receiving face arranged substantially horizontally. Thus presented, the slag stream 96 may be gravitationally directed thereonto. This is the simplest type of an arrangement for applying melt to a distributor and is made possible by the novel design of the jet system which produces the inclined blast 80. Its simplicity is immediately recognized by comparison with prior art apparatuses wherein application of the stream of fiber-forming material to a centrifuging surface was dependent upon ancillary devices such as accelerating wheels, back drafts, material-confining surfaces, updrafts and the like. Furthermore, horizontal disposition of the rotor surface provides further advantage in the elimination of gravitational slough-off of the melt stream 96 as is the tendency with any inclined centrifuging surface. Additionally, and quite importantly, this horizontal positioning, by eliminating such gravitational effects, provides for the maintenance of a supply reservoir of the fluid fiber-forming material in the central portion of the rotor face 12 which servesin stabilizing the centrifuging process especially with respect to uniformity of the rate of flow and the temperature of the fiber-forming material.

While the various dimensions in the apparatus may vary without departing from the scope of this invention, the acute angle which the blast 80 forms with the horizontal may vary between upper and lower limits beyond which the improved fiber-producing operation no longer obtains. The upper limit (largest angle) approximates that at which a core of return draft is developed in the blast 80. The lower limit (smallest angle) approaches that at which the blast 80 can no longer intersect the plane of centrifuging. Blast angles lying in the range of from ten to forty-five degrees (1045 are typically operable and practical.

More specifically, in the following are dimensions of a working embodiment of this invention, these being given as exemplary only and not as limitations as to the scope of the invention.

Rotor 10 diameter inches 11.5 Space between rotor plane 74 and upper surface of plate 44- (dimension a in FIG. 4) do /2 Diameter of jet passages 58 do 8 Spacing between centers of passages 58 do Forward inclination of passages 58 degrees 35 Spacing between rotor peripheries and intersection of jet axes with the plane 74' (dimension b, FIG.

4) inches %1 Melt rate pounds'per hour- 4450 Steam pressure p.s.i. gauge 6080 Radial clearance between rotor 10 periphery and edge of opening 56 inches A While I have described above the principles of my invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of my invention.

What is claimed is:

1. An apparatus for fabricating mineral fiber comprising a cylindrical rotor having a vertically extending shaft and an upwardly exposed slag-receiving face, said face being spherically concave and having an outer periphery which defines and lies in a horizontal plane, a supporting frame, said shaft and rotor being rotatably mounted on said frame for rotation about a vertical axis, said rotor being mounted on the upper end of said shaft, said shaft and rotor being hollow to receive therein a cooling flow of water, an upright tube disposed inside said hollow shaft and having a discharge end located in said hollow rotor, said tube having a radial clearance with said hollow shaft thereby providing a tubular discharge duct having inner and outer walls defined by said pipe and said shaft, respectively, a housing having diametrically opposite spaced apart front and rear portions, said housing being mounted on said frame and constituting a chamber which surrounds said rotor, said housing including an upper substantially flat horizontal plate having a central opening through which said rotor face projects, the plane of said rotor periphery lying above the upper surface of said plate, said plate having a series of spaced apart jet passages therethrough which surround said rotor and communicate with said chamber, said series being arranged in an eccentric pattern around said rotor, said pattern including two arcuate sections, the passages of one arcuate section being parallel and'inclined in a given forward direction at an angle of about thirty-five (35 with the horizontal, said one arcuate section being substantially bisected by a vertical plane which includes a diameter of said rotor face and is parallel to the passages of said one arcuate section, said one arcuate section extending around the front portion of said housing, said one arcuate section having an angular length of approximately three hundred fifteen degrees (315), the second arcuate section also being substantially bisected by said vertical plane and having a length of approximately forty-five degrees (45), the inner passages of said second section adjacent said vertical plane inclining upwardly and forwardly at an angle of approximately thirty-five degrees (35) with respect to the horizontal plane and diverging outwardly at an approximate angle of thirty degrees (30) with respect to said vertical plane, the remaining passages of said second section inclining upwardly and forwardly at an angle of approximately thirty-five degrees (35) with the horizontal and decreasing progressively in divergency outwardly from said inner passages until they become parallel to said vertical plane at the end extremities of said one arcuate section, said second arcuate section extending around the rear portion of said housing, all of said passages having axes respectively which when extended intersect the plane of said rotor periphery in a circular pattern substantially concentric with and spaced outwardly from said rotor periphery, means for directing steam under pressure into said chamber and through said passages, a slag trough disposed above said rotor face and serving to deliver a gravitating stream of molten slag onto that portion of said face which lies within the angle of divergency between said inner passages, said trough being disposed above and out of the path of said passage axes, means for rotating said rotor, the pressure of said steam and the rotational speed of said rotor being related such that molten slag will be centrifuged from said rotor face in filamentary streams which are attenuated into solidified filaments and carried upwardly and forwardly in substantial alignment with said passage axes, the rotational speed of said rotor being insufiicient to centrifuge said filamentary streams through the encircling steam blast from said series of passages; said steam-directing means including a straight section of conduit connected to said housing at the rearmost portion thereof and extending in line with said vertical plane, said straight section being inclined upwardly at an angle parallel to said passages; and a vertical partition in said chamber at the front thereof, said partition coinciding with said vertical plane.

2. An apparatus for fabricating mineral fiber comprising a cylindrical rotor having a vertically extending shaft and an upwardly exposed slag-receiving face, said face being spherically concave and having an outer periphery which defines and lies in a horizontal plane, a supporting frame, said shaft and rotor being rotatably mounted on said frame for rotation about a vertical axis, said rotor being mounted on the upper end of said shaft, said shaft and rotor being hollow to receive therein a cooling flow of Water, a housing having diametrically opposite spaced apart front and rear portions, said housing being mounted on said frame and enclosing a chamber which surrounds said rotor, said housing including an upper substantially flat horizontal plate having a central opening through which said rotor face projects, the plane of said rotor periphery lying above the upper surface of said plate, said plate having a series of spaced apart jet passages therethrough which surround said rotor and communicate with said chamber, said series being arranged in an eccentric pattern around said rotor, said pattern including two arcuate sections, the passages of one arcuate section being parallel and inclined in a given forward direction at an angle of about thirty-five degrees (35) with the horizontal, said one arcuate section being substantially bisected by a vertical plane which includes a diameter of said rotor face and is parallel to the passages of said one arcuate section, said one arcuate section extending around the front portion of said housing, said one arcuate section having an angular length of approximately three hundred fifteen degrees (315), the second arcuate section also being substantially bisected by said vertical plane and having a length of approximately forty-five degrees (45), the inner passages of said second section adjacent said vertical plane inclining upwardly and forwardly at an angle of approximately thirty-five degrees (35) with respect to the horizontal plane and diverging outwardly at an approximate angle of thirty degrees (30) with respect to said vertical plane, the remaining passages of said second section inclining upwardly and forwardly at an angle of approximately thirty-five degrees (35) with the horizontal and decreasing progressively in divergency outwardly from said inner passages until they become parallel to said vertical plane at the end extremities of said one arcuate section, said second arcuate section extending around the rear portion of said housing, all of said passages having axes respectively which when extended intersect the plane of said rotor periphery in a circular pattern substantially concentric with and spaced outwardly from said rotor periphery, means for direct ing steam under pressure into said chamber and through said passages, a slag trough disposed above said rotor face and serving to deliver a gravitating stream of molten slag onto that portion of said face which lies within the angle of divergency between said inner passages, said trough being disposed out of the path of said passage axes, means for rotating said rotor, the pressure of said steam and the rotational speed of said rotor being related such that molten slag will be centrifuged from said rotor face in filamentary streams which are attenuated 10 into solidified filaments and carried upwardly and forwardly in substantial alignment with said passage axes, the rotational speed of said rotor being insufficient to centrifuge said filamentary streams through the encircling steam blast from said series of passages.

3. An apparatus for fabricating mineral fiber comprising a cylindrical rotor having a vertically extending shaft and an upwardly exposed slag-receiving face, said face being spherically concave and having an outer periphery which defines and lies in a horizontal plane, a supporting frame, said shaft and rotor being rotatably mounted on said frame for rotation about a vertical axis, said rotor being mounted on the upper end of said shaft, said shaft and rotor being hollow to receive therein a cooling flow of water, a housing having diametrically opposite spaced apart front and rear portions, said housing being mounted on said frame and enclosing a chamber which surrounds said rotor, said housing including an upper substantially flat horizontal plate having a central opening through which said rotor face projects, the plane of said rotor periphery lying above the upper surface of said plate, said plate having a series of spaced apart jet passages therethrough which surround said rotor and communicate with said chamber, said series being arranged in an eccentric pattern around said rotor, said pattern including two arcuate sections, the passages of one arcuate section being parallel and inclined in a given forward direction at an angle of about thirty-five degrees (35) with the horizontal, said one arcuate section being substantially bisected by a vertical plane which is coincident with a diameter of said rotor face and parallel to the passages of said one arcuate section, said one arcuate section extending around the front portion of said housing, the second arcuate section also being substantially bisected by said vertical plane, the inner passages of said second section adjacent said vertical plane inclining upwardly and forwardly at an angle of approximately thirty-five degrees (35) with respect to the horizontal plane and diverging outwardly with respect to said vertical plane, the remaining passages of said second section inclining upwardly and forwardly at an angle of approximately thirty-five degrees (35) with the horizontal and decreasing progressively in divergency outwardly from said inner passages until they become parallel to said vertical plane at the end extremities of said one arcuate section, said second arcuate section extending around the rear portion of said housing, all of said passages having axes respectively which when extended intersect the plane of said rotor periphery in a circular pattern substantially concentric with and spaced outwardly from said rotor periphery, means for directing steam under pressure into said chamber and through said passages, a slag trough disposed above said rotor face and serving to deliver a gravitating stream of molten slag onto said rotor face, said trough being disposed out of the path of said passage axes, means for rotating said rotor, the pressure of said steam and the rotational speed of said rotor being related such that molten slag will be centrifuged from said rotor face in filamentary streams which are attenuated into solidified filaments and carried upwardly and forwardly in substantial alignment with said passage axes, the rotational speed of said rotor being insuflicient to centrifuge said filamentary streams through the encircling steam blast from said series of passages, the length of said one arcuate section being greater than that of said second arcuate section, said second arcuate section having a length which provides a gap in said encircling blast large enough to permit penetration of said gravitating stream through said encircling blast and onto said rotor face.

4. An apparatus for fabricating mineral fiber comprising a cylindrical rotor having a vertically extending shaft and an upwardly exposed slag-receiving face, said face being spherically concave and having an outer periphery which defines and lies in a horizontal plane, a supporting frame, said shaft and rotor being rotatably mounted on said frame for rotation about a vertical axis, said rotor being mounted on the upper end of said shaft, said shaft and rotor being hollow to receive therein a cooling flow of water, a housing having diametrically opposite spaced apart front and rear portions, said housing being mounted on said frame and enclosing a chamber which surrounds said rotor, said housing including an upper substantially flat horizontal plate having a central opening through which said rotor face projects, the plane of said rotor periphery lying above the upper surface of said plate, said plate having a series of spaced apart jet passages therethrough which surround said rotor and communicate with said chamber, said series being arranged in an eccentric pattern around said rotor, said pattern including two arcuate sections, the passages of one arcuate section being parallel and inclined in a given forward direction at an angle of about thirty-five degrees (35) with the horizontal, said one arcuate section being substantially bisected by a vertical plane which is coincident with a diameter of said rotor face and parallel to the passages of said one arcuate section, said one arcuate section extending around the front portion of said housing, the second arcuate section also being substantially bisected by said vertical plane, the inner passages of said second section adjacent said vertical plane inclining upwardly and forwardly at an angle of approximately thirty-five degrees (35) with respect to the horizontal plane and diverging outwardly with respect to said vertical plane, the remaining passages of said second section inclining upwardly and forwardly at an angle of approximately thirty-five degrees (35) with the horizontal and decreasing progressively in divergency outwardly from said inner passages until they become parallel to said vertical plane at the end extremities of said one arcuate section, said second arcuate section extending around the rear portion of said housing, all of said passages having axes respectively which when extended intersect the plane of said rotor periphery in a pattern which is radially spaced from said rotor periphery, means for directing steam under pressure into said chamber and through said passages, a slag trough disposed above said rotor face and serving to deliver a gravitating stream of molten slag onto said rotor face, said trough being disposed out of the path of said passage axes, means for rotating said rotor, the pressure of said steam and the rotational speed of said rotor being related such that molten slag will be centrifuged from said rotor face in filamentary streams which are attenuated into solidified filaments and carried upwardly and forwardly in substantial alignment with said passage axes, the rotational speed of said rotor being insufficient to centrifuge said filamentary streams through the encircling steam blast from said series of passages, the length of said one arcuate section being greater than that of said second arcuate section, said second arcuate section having a length which provides'a gap in said encircling blast large enough to permit penetration of said gravitating stream through said encircling blast and onto said rotor face.

5. An apparatus for fabricating mineral fiber comprising a cylindrical rotor having a vertically ertending shaft and an upwardly exposed slag-receiving face, said face being spherically concave and having an outer periphery which defines and lies in a horizontal plane, a supporting frame, said shaft and rotor being rotatably mounted on said frame for rotation about a vertical axis, said rotor being mounted on the upper end of said shaft, said shaft and rotor being hollow to receive therein a cooling flow of water, a housing having diametrically opposite spaced apart front and rear portions, said housing being mounted on said frame and enclosing a chamber which surrounds said rotor, said housing including a nozzle member which surrounds said rotor, said nozzle member being disposed below but adjacent to the periphery of said rotor, a series of spaced apart jet passages in said nozzle member which communicate with said chamber, said series being arranged in' a pattern surrounding said rotor, said pattern including two arcuate sections, said arcuate sections each being bisected by a vertical plane which is coincident with a diameter of said rotor, one arcuate section extending around the front portion of said nozzle member, the second arcuate section extending around the rear portion of said nozzle member, the passages of said one arcuate section being substantially parallel and inclined forwardly at an acute angle with respect to a horizontal plane, the passages of said second arcuate section being inclined forwardly at an acute angle with respect to a horizontal plane, the inner passages of said second section adjacent the opposite sides of said vertical plane diverging outwardly at an acute angle with respect to said vertical plane, the remaining passages of said second section outwardly from said inner passages progressively decreasing in divergency away from said vertical plane until they become parallel to the passages of said one arcuate section, all of said passages having locations and axes, respectively, which when extended intersect the plane of said rotor periphery in an encircling pattern spaced outwardly from said rotor periphery, means for directing steam under pressure into said chamber and through said passages, a slag trough having a delivery end disposed above said rotor face for delivering a gravitating stream of molten slag onto said face, said trough being disposed out of the path of said passage axes, the length of said one arcuate section being greater than that of said second arcuate section, said second arcuate section having a length which provides a well in the blast of steam emerging from said series of passages large enough to permit penetration of said gravitating stream through said blast and onto said rotor face, the acute angle of the passages of said one arcuate section being no greater than that which results in the development of a back draft through the central portion of the steam blast issuing from said series of passages and no less than that at which said steam blast intersects the plane of said rotor perimeter in the location of said encircling pattern.

6. An apparatus for fabricating mineral fiber comprising a cylindrical rotor having a vertically extending shaft and an upwardly exposed slag-receiving face, said face being spherically concave and having an outer periphery which defines and lies in a horizontal plane, a supporting frame, said shaft and rotor being rotatably mounted on said frame for rotation about a vertical axis, said rotor being mounted on the upper end of said shaft, said shaft and rotor being hollow to receive therein a cooling flow of water, a housing having diametrically opposite spaced apart front and rear portions, said housing being mounted on said frame and enclosing a chamber which surrounds said rotor, said housing including a nozzle member which surrounds said rotor, said nozzle member being disposed below but adjacent to the periphery of said rotor, a series of spaced apart jet passages in said nozzle member'which communicate with said chamber, said series being arranged in a pattern surrounding said rotor, said pattern including two arcuate sections, one arcuate section extending around the front portion of said nozzle member, the second arcuate section extending around the rear portion of said nozzle member, the passages of said one arcuate section being substantially parallel and inclined forwardly at an acute angle with respect to a horizontal plane, the passages of said second arcuate section being inclined forwardly at an acute angle with respect to a horizontal plane, two adjacent inner passages disposed between the ends of said second arcuate section diverging outwardly from each other at an acute angle, the remaining passages of said second section outwardly respectively from said inner passages progressively decreasing in divergency until they become parallel to the passages of said one arcuate section, all of said passages having locations and axes, respectively, which when extended intersect the plane of said rotor periphery in anencircling pattern spaced outwardly from said rotor periphery, means for directing steam under pressure into said chamber and through said passages, a slag trough having a delivery end disposed above said rotor face for delivering a gravitating stream of molten slag onto said face, said trough being disposed out of the path of said passage axes, the length of said one arcuate section being greater than that of said second arcuate section, said second arcuate section having a length which provides a well in the blast of steam emerging from said series of passages large enough to permit penetration of said gravitating stream through said blast and onto said rotor face, the acute angle of the passages of said one arcuate section being no greater than that which results in the development of a back draft through the central portion of the steam blast issuing from said series of passages and no less than that at which said steam blast intersects the plane of said rotor perimeter in the location of said encircling pattern.

7. An apparatus for fabricating mineral fiber comprising a cylindrical rotor having a vertically extending shaft and an upwardly exposed slag-receiving face, said face being spherically concave and having an outer periphery which defines and lies in a horizontal plane, a supporting frame, said shaft and rotor being rotatably mounted on said frame for rotation about a vertical axis, said rotor being mounted on the upper end of said shaft, said shaft and rotor being hollow to receive therein a cooling flow of water, a housing having diametrically opposite spaced apart front and rear portions, said housing being mounted on said frame and enclosing a chamber which surrounds said rotor, said housing including a nozzle member which surrounds said rotor, said nozzle member being disposed below but adjacent to the periphery of said rotor, 21 series of spaced apart jet passages in said nozzle member which communicate with said chamber, said series being arranged in a pattern surrounding said rotor, said pattern including two arcuate sections, one arcuate section extending around the front portion of said nozzle member, the second arcuate section extending around the rear portion of said nozzle member, the passages of said one arcuate section being substantially parallel and inclined forwardly at an acute angle with respect to a horizontal plane, the passages of said second arcuate section being inclined forwardly at an acute angle with respect to a horizontal plane, two adjacent inner passages situated between the ends of said second arcuate section lying on opposite sides of a vertical plane which includes a rotor face diameter and extends between the front and rear housing portions, said two inner passages diverging outwardly from said vertical plane at an acute angle, the remaining passages of said second arcuate section diverging outwardly at acute angles from the respective sides of said vertical plane, all of said passages having locations and axes, respectively, which when extended intersect the plane of said rotor periphery in an encircling pattern spaced outwardly from said rotor periphery, means for directing steam under pressure into said chamber and through said passages, a slag trough having a delivery end disposed above said rotor face for delivering a gravitating stream of molten slag onto said face, said trough being disposed out of the path of said passage axes, the length of said one arcuate section being greater than that of said second arcuate section, said second arcuate section having a length which provides a well in the blast of steam emerging from said series of passages large enough to permit penetration of said gravitating stream through said blast and onto said rotor face, the acute angle of the passages of said one arcuate section being no greater than that which results in the development of a back draft through the central portion of the steam blast issuing from said series of passages and no less than that at which said steam blast intersects the plane of said rotor perimeter in the location of said encircling pattern.

8. An apparatus for fabricating mineral fiber comprising a cylindrical rotor having an upwardly exposed slagreceiving face, said face being concave and having an outer periphery which defines and lies in a substantially horizontal plane, said rotor having a vertical axis and being mounted for rotation about its axis, a nozzle device having a series of jet passages in closely spaced relation, said series being arranged in a pattern surrounding said rotor and being spaced below said rotor periphery, said jet passages being inclined at an acute angle with the horizontal in a direction substantially parallel to a vertical plane which includes a diameter of said rotor face, said jet passages further being located such that the axes thereof intersect the plane of said rotor periphery in a pattern encircling said rotor periphery at a location spaced outwardly therefrom, means for delivering a gravitating stream of molten material onto the central portion of said rotor face to provide a reservoir of material in said central portion, a portion of said jet passages horizontally diverging away from said stream.

9. An apparatus for fabricating mineral fiber comprising a cylindrical rotor having an upwardly exposed slagreceiving face, said face being concave and having an outer periphery which defines and lies in a substantially horizontal plane, said rotor having a vertical axis and being mounted for rotation about its axis, said rotor having diametrically opposite spaced apart front and rear portions, delivery means for delivering a gravitating stream of molten material onto said rotor face, nozzle means for directing a gaseous blast inclined upwardly and forwardly in a given direction against molten material centrifuged from said rotor face for attenuating and solidifying said centrifuged material into fibers, said blast being elliptical in cross-section, said nozzle means including means for defining a well within said gaseous blast through which said gravitating stream falls onto said rotor face, said delivery means and said well being positioned to direct said gravitating stream into said well and onto the central port-ion of said face for providing a reservoir of molten material on said central portion, said nozzle means including a series of jet passages in closely spaced relation, said series being arranged in a pattern at least partially surrounding said rotor and being spaced below said rotor periphery, said jet passages being inclined upwardly and forwardly in said given direction.

10. An apparatus for fabricating mineral fiber comprising a cylindrical rotor having an upwardly exposed slag-receiving face, said face being concave and having an outer periphery which defines and lies in a substantially horizontal plane, said rotor having a vertical axis :and being mounted for rotation about its axis, said rotor having diametrically opposite spaced apart front and rear portions, delivery means for delivering a gravitating stream of molten material onto said rotor face, nozzle means for directing a gaseous blast inclined upwardly and forwardly in a given direction against molten material centrifuged from said rot-or face for attenuating and solidifying said centrifuged material into fibers, said blast being elliptical in cross-section, said nozzle means including means for defining a divergently shaped well within said gaseous blast through which said gravitating stream falls onto said rotor face, said well overlying said rotor face and diverging from the vicinity of said rear portion toward said forward portion, said delivering means being positioned to direct said gravitating stream into said well and said well being just large enough to receive said stream therethrough.

11. An apparatus for fabricating mineral fiber comprising a cylindrical rotor having an upwardly exposed slag-receiving face, said face being concave and having an outer periphery which defines and lies in a substantially horizontal plane, said rotor having a vertical axis and being mounted for rotation about its axis, said rotor having diametrically opposite spaced apart front and rear portions, delivery means for delivering a gravitating stream of molten material onto said rotor face, nozzle 15 16 means for directing a gaseous blast inclined 'upwardly References Cited and forwardly in a given direction against molten material UNITED STATES PATENTS centrifuged from said rotor face for attenuating and solidifying said centrifuged material into fibers, said blast 2,15 6382 4/1939 Hflrford et being elliptical in cross-section, said nozzle means in- 5 2 793:395 5/ 1957 Richardson 6514 eluding means for defining a well within said gaseous FOREIGN PATENTS blast through which said gravitating stream falls onto said rotor face, said delivery means and said well being :positioned to direct said gravitating stream into said well and onto the central portion of said face to provide a 1 DONALL SYLVESTER P'lmary Examiner reservoir of molten material on said central portion. 0 D. CRUPAIN, R. L. LINDSAY, Assistant Examiners.

716,917 1/ 1942 Germany. 

11. AN APPARATUS FOR FABRICATING MINERAL FIBER COMPRISING A CYLINDRICAL ROTOR HAVING AN UPWARDLY EXPOSED SLAG-RECEIVING FACE, SAID FACE BEING CONCAVE AND HAVING AN OUTER PERIPHERY WHICH DEFINES AND LIES IN A SUBSTANTIALLY HORIZONTAL PLANE, SAID ROTOR HAVING A VERTICAL AXIS AND BEING MOUNTED FOR ROTATION ABOUT ITS AXIS, SAID ROTOR HAVING DIAMETRICALLY OPPOSITE SPACED APARAT FRONT AND REAR PORTIONS, DELIVERY MEANS FOR DELIVERING A GRAVITATING STREAM OF MOLTEN MATERIAL ONTO SAID ROTOR FACE, NOZZLE MEANS FOR DIRECTING A GASEOUS BLAST INCLINED UPWARDLY AND FORWARDLY IN A GIVEN DIRECTION AGAINST MOLTEN MATERIAL CENTRIFUGED FROM SAID ROTOR FACE FOR ATTENUATING AND 